Unable to fly; Feet are born in the lowest part of the body, so they are upright; There is webbed toes; Plantation, other birds touch the ground with their toes; Forelimbs have fins; Feathers are short to reduce friction and turbulence; There is a layer of air between the feathers to keep warm. The back is black and the abdomen is white. Penguins are the largest flightless birds on earth.